<template>
  <view class="play">
    <!-- 模糊背景(靠样式设置), 固定定位 -->
    <view class="song-bg" :style="`background-image: url(${songInfo && songInfo.al && songInfo.al.picUrl
    }?imageView&thumbnail=360y360&quality=75&tostatic=0);`"></view>
    <!-- 留声机 - 容器 -->
    <view class="song-wrapper">
      <!-- 留声机本身(靠css动画做旋转) -->
      <!-- animation-play-state 规定动画是否正在运行或暂停。默认是 “running” -->
      <view class="song-turn ani" :style="`animation-play-state:${playState ? 'running' : 'paused'}`">
        <view class="song-img">
          <!-- &&写法是为了防止报错, 有字段再继续往下访问属性 -->
          <image style="width: 100%" :src="`${songInfo && songInfo.al && songInfo.al.picUrl
          }?imageView&thumbnail=360y360&quality=75&tostatic=0`" alt="" />
        </view>
      </view>
      <!-- 播放按钮 -->
      <view class="start-box" @click="audioStart">
        <text class="song-start" v-show="!playState"></text>
      </view>
      <!-- 播放歌词容器 -->
      <view class="song-msg">
        <!-- 歌曲名 -->
        <text class="m-song-h2">
          <text class="m-song-sname">{{ songInfo.name }}-{{
              songInfo && songInfo.ar && songInfo.ar[0].name
          }}</text>
        </text>
        <!-- 歌词部分-随着时间切换展示一句歌词 -->
        <view class="lrcContent">
          <text class="lrc">{{ curLyric }}</text>
        </view>
      </view>
      <!-- 留声机 - 唱臂 -->
      <view class="needle" :style="`transform: rotate(${needleDeg});`"></view>
    </view>
    <!-- 播放音乐真正的标签
      看接口文档: 音乐地址需要带id去获取(但是有的歌曲可能404)
      https://binaryify.github.io/NeteaseCloudMusicApi/#/?id=%e8%8e%b7%e5%8f%96%e9%9f%b3%e4%b9%90-url
     -->
    <!-- <audio ref="audio" :src="`https://music.163.com/song/media/outer/url?id=${id}.mp3`"></audio> -->
  </view>
</template>

<script>
  import {
    reactive,
    computed,
    toRefs,
    onBeforeUnmount
  } from 'vue'
  import {
    onLoad
  } from '@dcloudio/uni-app'
  import {
    playDetailAPI,
    playLyricsAPI
  } from '../../api/index.js'
  export default {
    setup() {
      let data = reactive({
        playState: false, // 音乐播放状态(true暂停, false播放)
        id: 0, // 上一页传过来的音乐id
        songInfo: {}, // 歌曲信息
        lyric: {}, // 歌词枚举对象(需要在js拿到歌词写代码处理后, 按照格式保存到这个对象)
        curLyric: '', // 当前显示哪句歌词
        lastLy: '' // 记录当前播放歌词
      })
      // 获取传递过来的歌曲ID
      onLoad((options) => {
        data.id = options.id
        showLyric()
        getSong()
        // 配置audio
        innerAudioContext.autoplay = true
        innerAudioContext.src = `https://music.163.com/song/media/outer/url?id=${data.id}`
      })
      // 创建audio组件
      const innerAudioContext = uni.createInnerAudioContext()
      // 留声机-唱臂的位置属性
      const needleDeg = computed(() => {
        return data.playState ? '-7deg' : '-38deg'
      })
      // 获取歌曲详情与歌词
      const getSong = async () => {
        const res = await playDetailAPI(data.id)
        data.songInfo = res.data.songs[0]
        const lyrContent = await playLyricsAPI(data.id)
        const lyricStr = lyrContent.data.lrc.lyric
        // 调用_formatLyr处理歌词
        data.lyric = _formatLyr(lyricStr)
        // 初始化完毕显示零秒歌词
        data.curLyric = data.lyric[0]
      }
      const _formatLyr = (lyricStr) => {
        let reg = /\[.+?\]/g
        // 匹配所有[]字符串以及里面的所有内容, 并返回数组
        let timerArr = lyricStr.match(reg)
        // 按照[]拆分歌词字符串, 返回一个数组(下标为0位置元素不要,后面的留下所以截取)
        let conenetArr = lyricStr.split(/\[.+?\]/).slice(1)
        // 保存歌词的对象, key是秒, value是显示的歌词
        let lyricObj = {}
        timerArr.forEach((item, index) => {
          // 拆分[00:00.000]这个格式字符串, 把分钟数字取出, 转换成秒
          let ms = item.split(':')[0].split('')[2] * 60
          // 继续拆分, 把十位的秒拿出来, 如果是0, 去拿下一位数字, 否则直接用2位的值
          let ss = item.split(':')[1].split('.')[0].split('')[0] === '0' ? item.split(':')[1].split('.')[0].split(
            '')[1] : item.split(':')[1].split('.')[0]
          // 秒数作为key, 对应歌词作为value
          lyricObj[ms + Number(ss)] = conenetArr[index]
        })
        // 返回得到的歌词对象
        return lyricObj
      }
      // 播放按钮 - 点击事件
      const audioStart = () => {
        if (!data.playState) {
          // 继续播放声音
          innerAudioContext.play()
        } else {
          // 暂停audio的播放
          innerAudioContext.pause()
        }
        data.playState = !data.playState
      }
      const showLyric = () => {
        // timeupdate 事件在音频/视频（audio/video）的播放位置发生改变时触发
        innerAudioContext.onTimeUpdate(() => {
          // currentTime 属性设置或返回音频/视频播放的当前位置（以秒计）。当设置该属性时，播放会跳跃到指定的位置
          let curTime = Math.floor(innerAudioContext.currentTime)
          // 避免空白出现
          if (data.lyric[curTime]) {
            data.curLyric = data.lyric[curTime]
            data.lastLy = data.curLyric
          } else {
            data.curLyric = data.lastLy
          }
        })
      }
      // 销毁前 结束音乐
      onBeforeUnmount(()=>{
        innerAudioContext.stop()
      })
      return {
        audioStart,
        ...toRefs(data),
        needleDeg
      }
    }
  }
</script>

<style lang="scss">
  .header {
    height: 50px;
  }

  .play {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
  }

  .song-bg {
    background-color: #161824;
    background-position: 50%;
    background-repeat: no-repeat;
    background-size: auto 100%;
    transform: scale(1.5);
    transform-origin: center;
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    height: 100%;
    overflow: hidden;
    z-index: 1;
    opacity: 1;
    filter: blur(25px);
    /*模糊背景 */
  }

  .song-bg::before {
    /*纯白色的图片做背景, 歌词白色看不到了, 在背景前加入一个黑色半透明蒙层解决 */
    content: " ";
    background: rgba(0, 0, 0, 0.5);
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
  }

  .song-wrapper {
    position: fixed;
    width: 247px;
    height: 247px;
    left: 50%;
    top: 50px;
    transform: translateX(-50%);
    z-index: 10001;
  }

  .song-turn {
    width: 100%;
    height: 100%;
    background: url("../../static/bg.png") no-repeat;
    background-size: 100%;
  }

  .start-box {
    position: absolute;
    width: 156px;
    height: 156px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .song-start {
    width: 56px;
    height: 56px;
    background: url("../../static/start.png");
    background-size: 100%;
  }

  .needle {
    position: absolute;
    transform-origin: left top;
    background: url("../../static/needle-ab.png") no-repeat;
    background-size: contain;
    width: 73px;
    height: 118px;
    top: -40px;
    left: 112px;
    transition: all 0.6s;
  }

  .song-img {
    width: 154px;
    height: 154px;
    position: absolute;
    left: 50%;
    top: 50%;
    overflow: hidden;
    border-radius: 50%;
    transform: translate(-50%, -50%);
  }

  .m-song-h2 {
    margin-top: 20px;
    text-align: center;
    font-size: 18px;
    color: #fefefe;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
  }

  .lrcContent {
    margin-top: 50px;
  }

  .lrc {
    font-size: 14px;
    color: #fff;
    text-align: center;
  }

  .left-incon {
    position: absolute;
    top: 10px;
    left: 10px;
    font-size: 24px;
    z-index: 10001;
    color: #fff;
  }

  .ani {
    animation: turn 5s linear infinite;
  }

  @keyframes turn {
    0% {
      -webkit-transform: rotate(0deg);
    }

    100% {
      -webkit-transform: rotate(360deg);
    }
  }
</style>
